Drilling machine

[Ed Weldon]

I would not recommend any attempt to weld on or near a functional part of an expensive ball bearing. There are other ways to accomplish the locating and confining rotation of an outer ball bearing race that do not risk physical distortion of its geometry. In a shop with scarce resources 4 small carefully carved wood wedges (with locking tapers in the inside corner openings of the square tube) anchored with some tree sap would work. Personally I'd prefer making those more or less triangular spacers from steel with a close slip fit and retaining them with a minimum of epoxy adhesive. When bearing replacement is required application of heat at about 200C will cause the epoxy to break down and be easily cleaned off the spacers and the inside of the tube.